The present invention relates generally to a proportioning pump having an integral orifice that controls the proportion of fluid in a mixture. More specifically, this invention relates to a proportioning pump employed in a frozen product system to regulate the amount of air combined with a mix to create a frozen product.
A proportioning pump controls the proportion of a fluid in a mixture. The proportioning pump commonly employs an orifice to regulate the proportion of the fluid in the mixture. For example, a first fluid and a second fluid are mixed in a mixing chamber to form a mixture. If the proportion of the first fluid is to be regulated, the first fluid flows through an orifice prior to entering the mixing chamber, and the second fluid flows unrestricted into the mixing chamber. The orifice controls the proportion of the first fluid in the mixture. If the orifice is larger, the proportion of the first fluid in the mixture increases. If the orifice is smaller, the proportion of the first fluid in the mixture decreases.
Frozen product systems commonly employ proportioning pumps in the preparation of frozen products, such as frozen beverages and frozen desserts, including milkshakes and soft serve ice cream. The frozen product is made of mix and air. The mix is stored in a hopper or other containing vessel. In the prior art, when the frozen product is to be prepared, a pump draws mix from the hopper into a mixing chamber. The pump also draws air from the atmosphere into the mixing chamber. The air is regulated by an orifice, the size of the orifice determining the amount of air that is combined with the mix in the mixing chamber. The air and mix combine in the mixing chamber to form a mixture. The mixture is pumped into a freezing cylinder where the mixture is refrigerated and scrapped to form the frozen product. When the frozen product is to be served, the frozen product is dispensed from the freezing cylinder. If the frozen product is a milkshake, the milkshake is pumped into a syrup chamber and mixed with a flavored syrup and is then dispensed for serving.
In one prior art system, the same mix is employed to create both soft serve ice cream and milkshakes. More air is added to the mix to form soft serve ice cream than is added to the mix to form a milkshake. Therefore, a different size orifice is used to create soft serve ice cream and milkshakes. The orifice used with a soft serve ice cream pump is larger than the orifice used with a milkshake pump to incorporate more air into the mix to form the mixture. A drawback to the prior art pumps is that during assembly, the components of a pump used to create soft serve ice cream can be confused with the components of a pump used to create milkshakes. For example, if the orifice of a milkshake pump is accidentally assembled in the soft serve ice cream pump, not enough air is combined with the mix.
The orifice that controls the air from the atmosphere into the mixing chamber is external. Therefore, the orifice is exposed to air and can dry out over time. If the orifice dries out, the air passage can be blocked, reducing the amount of air flowing through the orifice, affecting the consistency of the resulting frozen product and the frozen product overrun. Overrun is a measurement of the amount of air in the frozen product. If the orifice is exposed to air and exposed to user interface, the amount of overrun is not predicable. As overrun decreases, the amount of profit on the frozen product can decrease, as there is less air and more mix in the frozen product per unit volume, which can decrease profit because more mix is used. To prevent this, the orifice is usually removed and cleaned daily to prevent blockage of the air passage.
A gasket controls the flow of fluids into and out of the mixing chamber. In the prior art, the gasket is complex and includes several components, increasing the complexity of assembly of the pump.
There are several drawbacks to the proportioning pump of the prior art. For one, the pump includes numerous components, making assembly of the pump complex. Additionally, the pump does not include any fail-safe mechanism to ensure the pump is assembled properly and that the components of different pumps are not confused. Finally, the external orifice must be removed daily and cleaned, requiring additional labor.